This is probably one of the wisest things anyone can ever do or say. Just let it go. It works for anything. Mainly though, what happens is when you let something go you no longer worry about it, obsess over it, or crave it or whatever. The stress of the situation or just the thoughts alone are lifted from your mind and you are free to just be.
At this point you are also able to recognize the fact that if something is meant to be it will be. It might take a while, however, it will still be.
I notice a lot of people, including myself, have a lot of trouble letting things go. We always think “If only I had done that.” or “If I can do this then…” or even “Thats not what should’ve happened.” You get the point. The thing is, if we are constantly bringing ourselves back to the same situation, even after its over, we are not keeping ourselves open to the new opportunities that may appear. We will miss them because we are still in our old mindset.
If you are stuck in a rut right now, maybe try looking around yourself and see if there’s something that you need to let go of that you haven’t. It might be the very thing that has kept you in the rut.